bowman



N. K. BOWMAN.

WALL ANCHOR.

APPLICATION FILED JULY 2 19'"!- Patented July 22, 1919.

2 SHEETS-SHEET I (1H0: mu

N. K. BOWMAN.

WALL ANCHOR.

APPLICATION FILED JULY 2.19m.

is of soft-clay which will let the braces sink NITED STATES orrc.

NEWTON K. BOWMAN, OF NORTH LAWRENCE, OHIO, ASSIGNOR TO THE AMERICAN MINE DOOR COMPANY, A CORPORATION OF OHIO.

WALL-ANCHOR.

Specification of Letters Patent.

Patented July 22, 1919.

To all whom it may concern:

Be it known that I, NEWTON K. BOWMAN, a citizen of the United States, residing at North Lawrence, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in all-Anchors, of which the following is a specification.

This invention relates to new and useful improvements in anchoring devices and more particularly to a novel form of wall anchor especially designed for anchoring short wall minin machines in the tunnels of coal mines and t e like.

It is common practice at the present time, particularly in coal mines, to under out the face or breast of a tunnel with a suitable mining machine and to then break the coal above down into the opening thus formed. To do this it is necessary thatsome means be provided for holding the under cutting or mining machine against the breast of the wall. In many instances braces are placed against the rear of the machine and against the bottom of the tunnel but this is unsatisfactory as often times the floor of the tunnel and loosen the machine. In other instances expansion bolts or equivalent devices are driven into the wall above the part to be under cut and a guy rope is extended from them to the rear of the machine. These expansion bolts, however, are of such a type I that much labor and time must be consumed in freeing them from the wall after use.

Being familiar with the above conditions, one of the primary objects of the present invention resides in the provision of a wall anchor which may be readily inserted in a comparatively small hole drilled in the face of the wall and quickly manipulated so that it may be locked in said wall, the construction of the anchor being such that it may be quickly operated so as to permit its ready release from the wall after use. A further object of the invention is to provide a wall anchor including a shell having an expanding element slidably mounted therein and coacting with a pair of gripping dogs, means being provided at one end of the expanding element for attachment to an anchoring cable so that after the dogs have been moved to gripping position by engagement with the expanding element the tension or stress of the anchoring cable on the expanding element will tend to actuate said expanding element to further force the dogs into the coal.

With these and other objects in view, my invention will be more fully described, illustrated in the accompanying drawings, and then specifically pointed out in the claims which are attached to and form a part of this application.

In the drawings:

Figure 1 is a top plan view partly in sect1on showing the improved anchor embedded in the breast of a tunnel and in operative posltion with respect to a short wall mining machine;

Fig. 2 is a longitudinal sectional view showing the position of the various parts comprising the wall anchor after said anchor has been inserted in the breast of a tunnel and before theexpanding element has been actuated to operate the gripping dogs;

Fig. 3 is a similar View showing the dogs moved to operative position by the expanding element;

Fig. 4 is a similar view showing the position of the several parts after the anchoring cable has been placed under tension;

Fig. 5 is a perspective View of the wall anchor detached;

Fig. 6 is a perspective view of the different parts comprising the wall anchor detached;

Fig. 7 is a transverse sectional View taken on the line 7-7 of Fig. 2;

Fig. 8 is a similar vlew taken on the line 8-8 of Fig. .3.

The improved device forming the subjectmatter of the present invention is principally designed for anchoring mining machines in the tunnels of coal mines and in Fig. 1 of the drawingsthe anchor is shown embedded in the breast 5 of a tunnel and operatively connected through the medium of a cable 6 with a short wall mining machine, indicated at 7.

Thedevice comprises a cylindrical shell or casing 8 having its outer end" provided with oppositely disposed stop lugs 9, the terannular stop shoulder 16 and a terminal hook 17 adapted to receive one end of a cable 6 whereby the cable may be detachably secured to the wall anchor. The free end ofv the expanding element 15 projects longitud-inally beyond the adjacent end of the casing 8 and the upper and lower faces f said expanding element are provlded with grooves 18 in which are seated gripping dogs or shoes 19, the grooves 18 are dovetailed in cross section while the gripping dogs 19 are correspondingly dovetailed, as best shown in Fig. 7 of the drawings, so as to prevent accidental dis lacement of the gripping dogs, while at t e same time allowing said dogs to be moved longitudinally with respect to the expanding element. he bottom walls of the grooves 18 are inclined toward the center of the expanding element so as to form a wedge-shaped terminal and thus force the gripping dogs outwardly into engagement with the coal when the expanding element is adjusted longitudinally within the casing. The gripping dogs 19 are preferably provided with one or more transverse teeth 20 adapted to bite into the coal and prevent accidental displacement of the anchor when tension is exerted on the cable 6. The inner ends of the dogs 19 are provided with longitudinally extending ears 21 having threaded openings 22 formed therein and adapted to receive correspondingly threaded screws 23. The heads of the screws 23 pass loosely through correspondingly shaped openings 24 formed in the casing 8 and serve to anchor the gripping dogs with respect to the casing, while at the same time permitting said dogs to expand and contract laterally according to the position of the expanding element. The grooves 18 are preferably disposed in longitudinal alinement with the lugs 10, although if desired, said grooves may be arranged at right angles thereto and any desired number of grooves and anchoring dogs may be employed as may be found desirable or necessary to the proper operation of the anchor.

In use a 'hole of suitable dimensions, usually two inches in diameter and about fifteen inches deep, is drilled in the breast 5 of the tunnel and the anchor with the parts in the position shown in Fig. 2 is inserted in this hole, after which the actuat ing member or rod 11 is rotated so as to draw the expandingelement longitudinally of the casing and force'the gripping dogs laterally into engagement with the coal, as best shown in Fig. 3 of the drawings. The anchoring cable 6 is then attached to the hook 17 and the winch or drum 23 of the mining machine rotated so as to place the cable 6 under tension, the tension of the cable 6 serving to move the rod 11 to the position shown in Fig. 4 of the drawings and in so doing forces the gripping shoes 19- with greater pressure against the coal. It

mits the casing and its associated parts to be readily removed from the hole in the wall of the tunnel. It will here be noted that owing to thejdovetailed formation of the grooves 18, the gripping dogs will be forced outwardly or inwardly according to the direction of movement of the expanding. element, the parts being so arranged that the greater the pull on the expanding element the tighter the dogs will bite into the coal.

While the anchor is principally designed for use in connection with mining machinery, it will, of course, be understood that said device may be employed for any purpose for which it may be found desirable or applicable without departing from the spirit of the invention.

Having thus described my invention, What is claimed as new is:

1. A wall anchor including a casing, an expanding element slidably mounted within the casing and provided with oppositely disposed grooves the walls of which'are inclined, gripping dogs normally seated in and bearing against the inclined walls of said grooves and each having its inner end provided with a pin and slot connection with the casing, and an actuating member having its inner end operatively connected with the expanding element and its outer end provided with means for engagement with a cable, said actuating member when rotated serving to move the dogs to gripping position.

2. A wall anchor including a casing having one end thereof provided with laterally extending lugs and its other end formed with oppositely disposed openings, an expanding element slidably mounted within the casing and provided with longitudinal grooves, the bottom walls of which are inclined, gripping dogs slidably mounted in the grooves and provided with ears, fastening devices .loosely passing through the openin s in the casing and secured to the ears 0 the gripping dogs, and a rod, one end of which is provided with means for attachment to a cable and its other end connected with the expandin element.

3. A wall anchor 'inclu ing a casing having one end thereof provided with oppositely disposed openings, an expanding element slidably mounted within the casing tionoof the expanding element,

end connected with the expanding elementl {L A wall anchor including a casing, an expanding element slidably mounted within the casing and having its outer end provided with a wedge-shaped portion and its inner end formed with a threaded socket, gripping dogs bearing against the wedge-shaped pora connection between the gripping dogs and the casing, a rod mounted for rotation within the easing and having its inner end provided with a threaded shank engaging the threads of the socket, the outer end of the rod being provided with a shoulder adapted to bear against the adjacent end of the casing and having a terminal hook adjacent said shoulder for engagement with an anchoring cable. y

5. A wall anchor including'a casing, an expanding element disposed within the casing and provided with a seating groove having an inclined wall, a gripping dog seated in said roove and normally bearing against the inclined wall thereof and having its inner end provided with a pin and slot con- -I1ecti0n with the casing, an actuating member mounted for rotation within the casing for movlng the dog to gripping position,

and means carried by the actuating member for engagement with a cable, the tension ofthe cable serving to partially withdraw the actuating member from the casing and further expand the gripping dog.

6. An anchoring device lncluding a casing, an expanding element disposed within the casing and including a wedge-shaped portion, gripping dogs bearing against the wedge-shaped portion of the expanding element and operatively connected with the casing, an actuating member operatively connected with the expanding element and rotatable within the casing for moving the dogs to gripping position, a cable secured to the actuating member, and means for placing the cable under tension whereby to exert a longitudinal pull on the actuating member and impart an additional outward force to the gripping dogs.

7. A Wall anchor including a casing, an expanding element slidably mounted within the casing and including a wedge-shaped portion, and gripping dogs engaging the wedge-shaped portion of the expanding element andoperatively connected with the casing whereby longitudinal movement of the expanding element within the casing will force the dogs laterally in a straight line to gripping position.

8. A wall anchor including a casing, an expanding element slidably mounted within the casing provided with oppositely disposed grooves the walls of which are inclined, and gripping dogs bearing against the inclined walls of said grooves and havin their inner ends operatively connected with the casing whereby longitudinal movement of the expanding element will force the dogs laterally in a straight line to grippin posltion.

In testimony whereof I a x my signature.

NEWTON K. BOWMAN. a 8.] 

